This is a simple-stupid “unix import system” for nix, for referencing
binaries in `/bin/` by their name and lifting them to a Nix attrset.
Allows for simple aliasing of executable names.
Change-Id: Ifa23cb377201c3b08050c5026e9751e736afaf56
Reviewed-on: https://cl.tvl.fyi/c/depot/+/664
Reviewed-by: tazjin <mail@tazj.in>
